Converting between forms
- Fraction to decimal: divide the numerator by the denominator: 3/8 = 3 ÷ 8 = 0.375.
- Decimal to percentage: multiply by 100: 0.35 = 35%.
- Percentage to decimal: divide by 100: 65% = 0.65.
- Percentage to fraction: write over 100 and simplify: 40% = 40/100 = 2/5.
- Decimal to fraction: use place value: 0.125 = 125/1000 = 1/8.
Useful facts to learn
- 1/2 = 0.5 = 50%; 1/4 = 0.25 = 25%; 3/4 = 0.75 = 75%.
- 1/5 = 0.2 = 20%; 1/10 = 0.1 = 10%; 1/8 = 0.125 = 12.5%.
- 1/3 = 0.333… ≈ 33.3%; 2/3 = 0.666… ≈ 66.7%.
Ordering
- To order a mix of fractions, decimals and percentages, convert them all to the same form, usually decimals.
- Example: 0.3, 1/4 and 28% are 0.3, 0.25 and 0.28, so the order is 1/4, 28%, 0.3.
Key terms
- Fraction
- A part of a whole, written as one number over another.
- Decimal
- A number with digits after a decimal point.
- Percentage
- A number out of 100.
- Equivalent
- Having the same value.
- Convert
- Change from one form to another.